This was a multi-center, multiple dose study in patients with moderate to severe psoriasis (a randomized, placebo-controlled, double-blind, serial 4 panel design) Dose levels included 0.15 mg/kg, 0.30 mg/kg, and 0.45 mg/kg q 12 hr. and patients were to receive therapy for 2 weeks. Based on results from these dose levels, patients were then to be treated in the second part of the study at the best dosage schedule and also randomized to receive placebo or cyclosporine for 8 weeks. However, based on results for the first part of the study, the second part of the protocol was modified. The higher dose was reduced to 0.26 mg/kg q 12 hr. and the treatment extension was extended to 12 weeks. This was continued as a separate protocol now in progress in the CRC. (A multicenter randomized, double-blind, parallel-group, multiple oral dose study to evaluate the tolerability and efficacy of L-733725 versus cyclosporine A versus placebo in the treatment of patients with moderate to severe chronic plaque-type psoriasis).